The present invention relates generally to a near surface vehicle and more particularly to a near surface vehicle combining ground effect and aerodynamic functions in a single vehicle.
Numerous types of ground effect vehicles have been developed for the purpose of improving near ground travel by utilizing the ground effect aerodynamic lift available in close proximity to the ground. The ground effect phenomenon results in higher lift versus drag ratios than are available in standard high altitude fixed wing vehicles or aircraft.
Some types of ground effect vehicles rely on a supporting air cushion to maintain the vehicle clearance over the ground or water surface. Such vehicles waste a considerable portion of their power in developing and then maintaining the required air cushion. Most ground effect vehicles include a skirt of flexible material around parts or all of the underside of the vehicle. This single air cushion can be divided to enhance the vehicle stability, as disclosed in various prior art vehicles. To avoid plow-in and roll problems such skirt heights typically are limited, which effects the crew and passenger comfort and limits wave or other obstacle clearance. Further, these ground effect vehicles generally are aerodynamically inefficient and extremely noisy.
A number of types of airfoil ground effect vehicles have been developed. Some types have conventional high aspect ratio's of six or above, but such vehicles have very large wing spans which makes these impractical vehicles to operate in restrictive areas such as harbors and sea ports. Other vehicle types have a low aspect ratio of about two or below. These airfoils or wings have low aerodynamic efficiency and hence end plates have been added to such designs to enhance lift. These vehicles typically do not have any or have severely limited hovering capability.
It therefore would be desirable to provide an improved near surface vehicle which combines the airfoil aerodynamics with the air cushion lift capability of air cushion type vehicles.